Cancerous or benign lesions of the GI tract often start in the mucosal layer of the stomach or intestines. With improved diagnostics and screening, such lesions are being identified prior to extension into the wall of the stomach or intestines. Unfortunately, definitive therapy has historically involved invasive surgical resection of the lesion and adjacent bowel. Treatment of such early lesions by local excision of the mucosal, with access via natural orifices, would represent a far less invasive approach.
Existing approaches to local mucosal resection have utilized a variety of endoscopic instruments. Current methods can be described as “suck and cut” or “lift and cut”. In the suck and cut method, a chamber attached to the end of the endoscope is placed near the lesion, suction is applied to draw the lesion into the chamber, an electrosurgical snare within the chamber is then activated to excise the entrapped tissue. This is done repeatedly to completely resect the affected tissue. In the lift and cut method, a two-channel endoscope is used. Through one channel of the endoscope a grasper is passed to lift the lesion. An electrosurgical snare, passed through the other endoscope channel is placed around the shaft of the grasper and advanced to encircle the lifted tissue. The snare is then activated to excise the tissue. Both approaches are commonly preceded by injecting saline or other solutions under the mucosal to raise the lesion away from the underlying muscle wall in an effort to limit perforation. This lesion, common in the art, is known as a “bleb”.
UK Patent Application GB 2365340A to Appleyard and Swain discloses a tissue resection device for removing tissue with a cavity of variable volume, which patent application is incorporated herein by reference.
Other devices and methods have been proposed for providing resection of tissue. Still, scientists and engineers continue to seek improved methods for the resection of tissue in the gastro-intestinal tract.